Spruce,

Try and avoid the uncoated multistrand wires for flyfishing. The stuff simply can't cope with the rigours of flycasting and ends up fraying and kinking.

I've spent a few years now trial and error with all sorts of wire and my recommendations would be either single-strand Titanium (AFW) in 40lb b/s or a nylon coated wire such as Loop Pike Wire or Surflon Micro Supreme 7x7 26lb b/s. Both types are knottable (although with the titanium I'd recommend a clip for attaching the fly) and avoid the need for a swivel which just adds unwanted weight.

The titanium is very kink resistant - I managed to get my trace caught round the engine prop when playing a fish last Autumn, not only did it remain intact and I landed the Pike but it didn't even kink! The nylon coated stuff (Loop/Surflon) is more susceptible to kinking but is extremely easy to use and very supple. Just start with a long trace at first (24" or so...) and if you get a fish that does kink it near the fly, just cut off and re-tie (use a jam knot). You will get several fly changes before having to replace the trace. Hope that makes sense?

Dougie